The present invention relates to measurement instruments and, more particularly, to a flexible, efficient, and easy-to-use mechanical-to-electrical measurement instrument.
Measurement instruments are growing in popularity because of their small size and increasing functionality. However, despite the advances of size and functionality, many mechanical-to-electrical measurement instruments still require continual monitoring and calibration to retain measurement accuracy.
For example, an electronic device for measuring pressure (an electronic pressure gauge) must often be compared to a known reference, such as a mechanical pressure standard. This is often due to the inability of a pressure to electric transducer or other component(s) to maintain an accurate output. As a result, many such electronic devices include electronic output adjustments. For example, potentiometers or variable resistors are often included to allow a user to monitor and calibrate these electronic devices to a known reference.
In typical operation, an electronic pressure gauge goes through a routine monitoring cycle. Periodically, the output of the electronic pressure gauge is recorded. The pressure source is then measured by a reference pressure standard. If the output from the reference pressure standard is equal to the output from the electronic pressure gauge, then the gauge is assumed to be operating properly.
The electronic pressure gauge may also (or alternatively) go through a routine calibration cycle. A typical calibration cycle requires that the electronic pressure gauge be removed from the pressure source and connected to a source with a known output. To pass calibration, the electronic pressure gauge must provide an output that is equal (within limits) to the known output. The known output can be adjusted throughout an operating range to calibrate the electronic pressure gauge across that range.
What is needed is an electronic pressure gauge that is easy to monitor and/or calibrate, and is relatively small and functional.
A technological advance is achieved by an electronic pressure instrument that is easy to monitor and calibrate, and is relatively small and functional. In one embodiment, the electronic pressure instrument includes two pressure inputs for receiving two fluids, which can eventually be provided to a sensor/transducer for converting a pressure differential of the two fluids to an electrical signal. Positioned between the two pressure inputs and the transducer is a rotatable valve having a mechanical test port and a plurality of conduits for selectively directing at least one of the fluids to the transducer or the mechanical test port. When the valve is in a first position, the two fluids are directed to the transducer. When the valve is in a second position, the at least one fluid is directed to the mechanical test port.
In some embodiments, when the valve is in the second position, the at least one fluid is also directed to the transducer.
In some embodiments, when the valve is being rotated to the second position, at least one fluid is continually directed to the transducer.
In some embodiments, when the valve is in a third position, the first and second fluids are diverted from the transducer. In some embodiments, when the valve is in the third position, the conduits are operable to direct two different fluids from the mechanical test port to the transducer.
In some embodiments, the conduits are operable only when test lines have been engaged with the mechanical test port.
In some embodiments, the mechanical test port is operable to rotate the valve by engaging test lines with the mechanical test port and rotating the test lines.
In some embodiments, the valve includes a spring for returning the valve to the first position whenever the test lines are disengaged with the mechanical test port.
In some embodiments, the instrument includes an electrical test port for receiving an external electrical test device, thereby allowing the device to monitor an output of the transducer.
In some embodiments, a DIN rail clip is included for mounting the instrument onto a pair of DIN rails.